Re: ECPG patch to use prepare for improved performance

This updated patch for ECPG uses the current routines by
default. If an environment variable (ECPGUSEPREPARE) is set
to "yes", it uses the new routine that prepares and
caches each statement.

-----Original Message-----
From: Michael Meskes [mailto:meskes(at)postgresql(dot)org]
Sent: Thursday, May 10, 2007 3:01 AM
To: William Lawrance
Cc: Michael Meskes; Pgsql-Patches
Subject: Re: [PATCHES] ECPG patch to use prepare for improved
performance

On Wed, May 09, 2007 at 01:12:17PM -0700, William Lawrance wrote:
> 2. The performance was improved by about 1 hour in the 3 hour
> elapsed time of the application. This is important to the
> customer in terms of accomplishing his work load in the
> time that has been allotted, based on his experience with DB2.
> Without this improvement, he is likely to consider it too slow.

But this only holds for one customer. I don't think this will hold for
every single application. At least I do not see a reason why this
should hold everytime.

> I would like to emphasize that we aren't measuring an artificial
> test program; this is a real customer's application. We loaded
> 7 million rows into 217 tables to run the application. I believe
> it is representative of many real batch applications.

But how about non-batch applications?

> Is there reason not to prepare each statement?

I'm completely against forcing such a design decision on the programmer.
Hopefully I will be able to add a real prepare statement soon.

> Could it be predicated upon a user supplied option ?

Yes, this is fine with me. If you could rearrange the patch I will test
and commit it.

Michael
--
Michael Meskes
Email: Michael at Fam-Meskes dot De, Michael at Meskes dot (De|Com|Net|Org)
ICQ: 179140304, AIM/Yahoo: michaelmeskes, Jabber: meskes(at)jabber(dot)org
Go SF 49ers! Go Rhein Fire! Use Debian GNU/Linux! Use PostgreSQL!